Insulating substance



20 value in this suggestion inasmuc the material became exceedingly Reiuued Nov. 25, 1924.

UNITED STATES PATENT OFFICE.

.' OI CHICAGO, ILLINOIS.

HAROLD S. ASHENHURST, OF CHICAGO, ILLINOIS, AS SIGNOB 'I'O HERBERT A. PARKYN, i

INSULATING SUBSTANCE.

No Drawing. Original No. 1,402,183, dated January 8,

Retail No. 15,844, dated May 27, 1924,

for reissue filed July 18, 1924. Serial No. 726,898.

To all whom it may concern:

Be it known that I, HAROLD S. Asrrlm- Htms'r, a citizen of the United States, and resident of Chicago, in the county of Cook 5 and'State of Illinois, have invented a certain new and useful Improvement in an Insulating Substance, of which the followis a specification.

y invention relates to heat insulating l0 materials and particula'rly to a novel improvement in the composition of matter described in my prior Patent N 0. 1,230,085.

In that patent I disclosed a com osition of matter the major constituent 0 which was asbestos in comminuted form and sugpossibility of employing other refractory materials including calcium sulphate or gypsum. However, long experiments failed to demonstrate an practical as an 1nsulating material of sufiicient lightness could not be roduced by employing calcium sulphate as isclosed in that patent. While the reactions were 'prompt an vigorous and gested the porous in character, it would not remain in that con dition but immediately fell. In other I words, while the mass seemed to rise in amost satisfactory manner and gave promise I of the production of a solid bodyof extreme lightness, 'it invariably fell and 'in its final form was much too heavy to be of practical use.

I have discovered a. means of obviating this tendency and am able to produce an insulati'ng' material of extreme lightness; that is, one in which the cellular most pronounced and which form. The result is secured small quantity of a so-called is stable in by a ret'arder to principal constituent to.

the sum as the hi is added chemicals similar to those proposed in my'prior patent heretofore referred to. I am able to produce a substance as light as 12 pounds per cubic foot having a s ecific' vity as low as 0.19. This as will mail? be understood, is of enormous high insulating structure is expands or advantage not economy in the constituent.

Preferably also I use of gypsum as the major mix with the materials a small quantity of fibrous material such as long fiber asbestos, or in the event the material is to be used where high heat is not to be resisted, cocoa or similar organic fibers. These fibers serve as reinforcements and strengthen the body of the material without adding to the weight thereof.

In practice a satisfactory result may be secured by combining approximately 4 pounds of a suitable retarder with each ton of gypsum. This is a commercial product and is so furnished cerns which market the material.

In making up the compound herein described I prefer to employ approximately parts by volume of the so-described gypsum, 2 parts by volume of magnesium carbonate and 2 parts by volume of aluminum sulphate. The carbonate emplo ed, whether it be that specified or some of t bonates, is insoluble in water, but the aluminum sulphate, in commercial form, is soluble. Its reaction with water results in releasing a free acid-in this case sulphuric acid-which in turn reacts with the carbonate, releasing carbon dioxide. Where a reinforcing elementis to be emplo ed I may add long fiber asbestos or cocoa fi r in the proportion ofapproximately 5% by wei ht of the mass. This compound in its ry state is inert. However, when it is to be utilized a quantity of water is added. thereto sufiicient to make a thick paste whereupon the leavening actionbeginsand the mass rises, the final volume bein man times that of the mixture as form Whil e stability of form is secured within a short time, the final hardening is not com,

"plete for 24 hours.

only because of the relatively capacity but because of the e other car-- y attributable to the slowwhendesired by the con-f of the reaction products of a finely of the reaction sulphate which .inaj or ingre this is merely incidental to the colloidal effeet which follows the use of the particular retarder, I am not aware. 'I wis it to be understood, therefore, that the word retarder is used as a broad term and that I intend to include within the scope of the term, as used in the claims, such other substances as will have the efiect of preventing the escape of the and the consequent collapse ofthe cel ular'structure, prior to hydraulic setting of the mass. I

B the word psum as used in the specification and c aims'l refer to calcium has been partially calcined will hydraulically set.

the chemicals specified in to employ all of desirable result.

order to secure a I claim:

1. A new composition of matter composed of the reaction tarding chemica nesium carbonate and water.

2. A new composition of matter composed of the reaction'products of gypsum as the em, a retarder, a lurality of substances which when combine with water evolve a gas and produce a cellular structure, and approximately 5% by weight of fiber asbestos.

3. A cellular substance formed by the liberation of gas due to chemical reactions within a mass of hydraulically setting material, said substance being composed of the reaction products of calcium su phate as the major ingredient, a water-insoluble carbonate, a substance having in water solution an acid reaction with the carbonate, whereby carbon dioxide is released, a retarder, and water.

v 4. -A new composition of matter having a pronounced cellular structure and compo divided material which. will hydraulically) set as the major ingredient, a 'water-insolu le carbonate, a substance having in water-solution an acid reaction with the carbonatewhereby carbon dioxide is released, a retarder, and 'water.

5. A new compos'tion of matter having a pronounced cellular structure and composed products of a finely divided material, which will hydraulically set, as its major ingredient, an insoluble carbonate, a retarder,-'a nd a solid which upon the addirelease an aci which will the ca bonate to release care said finely divided material bein turn act on 'bon dioxide,

ing" inert relative to the gas-forming sub-' stances. V I I r 6; A new composition of matterhaving a pronounced cellular structure and composed of the reaction products of a finely divided material, .which' will hydraulically set,

,ide.

roducts of gypsum, a re-, aluminum sulphate, magacting in the, presence stances reacting in the which will in turn act on the carbonate to release carbondiox- 8. A new composition of matter having a pronounced cellular structure and composed of the reaction products of calcium sulphate, an insoluble. carbonate, a retarder, and a solid which upon the addition of water will release an acid which will in turn react with the carbonate to release carbon dioxide.

9. The herein described composition of matter having a cellular formation and comd of the reaction products of calcium sulphate as the major ingredient, aluminum sulphate a solid which on the addition of water re eases an acid, an insoluble carbonate, -a retarder, and .water.

10. A' new com osition of matter having a pronounced cellu ar structure and composed of the reaction products of calcium sul hate, a retarder, water, and a plurality 0 substances which in the presence of water evolve a gas, said substances remainin chemically inert relative to said calcium su phate.

11. A dry mixture composed of a finely divided material which will hydraulically set, an insoluble carbonate, a retarder and will react withthe carbon'ate to carbon dioxide, the described release the substances re of water to produce a cellularstructure, said finel divided mate- 7 rial being inert relative to t e gas-forming chemicals.

12. A dry mixture composed of a finely divided material which will hydraulically set, an insoluble .carbonate,-a retarder and aluminum sulphate, in the presence of water to produce a cellular structure.-

13. A dry mixture composed of calcium sul hate, an insoluble carbonate, a'retarder,

an a water-soluble solid which, in once of water,-will release an acid, which acid will react withthe carbonate to produce carbon dioxide, the described sub.-

presence produce a cellularstructure and tohydrauli callyset in that condition. r

14. A dry mixture of the presinsoluble carbonate, a retarder, and alumifnum sulphate, which substances on the addi tion of water react to rodu'ce a cellular structureand to hydrau ically set'in'fthat condition. A 4

on the addition which substances react of water to calcium sulphate, an

15. A dry mixture composed of calcium sulphate, a retarder, and a plurality of sub stances which in the presence of water evolve a gas, said substances in dry condition and in the presence of water bein inert relative to said calcium su phate.

16. A new composition of matter comprising calcium sulphate, a xetarder and a pluchemically rality of substances which when mixed with water evolve a gas and form a cellular structure, said substances in the presence of water remaining chemically inert relative to said calcium sulphate.

Signed at Chicago, Illinois, this 7th day of July, 1924.

HAROLD ASHENHURST. 

